Mounting for drain valve in molded bowl



March 26, 1957 P. G. CARLSTEDT MOUNTING FOR DRAIN VALVE IN MOLDED BOWL Filed March 29, 1952 l ll 2 IL 46 y WZa/n/w, 6mm V wgiiomgs.

United States, O

Phillip G. Carlstedt, Oak Park, Ill., assignor to Hannifin Corporation, Chicago, IlL, a corporation of Illinois Application March 29, 1952, Serial No. 279,365

6 Claims. (Cl. 251-144) My invention relates to filters and is more particularly concerned with the mounting of the drain valve in the lower end of the filter bowl.

In commercial filters it is common to provide a drain valve in the lower end of the filter bowl with the valve parts mounted in a metal sleeve or insert which is cast or molded into the glass or plastic bowl, the insert being internally threaded to facilitate mounting of the valve parts therein. Two difficulties have been encountered with this construction where applied to a plastic bowl subjected to air pressures on the order of 150 pounds per square inch. In some instances a tight seal is not effected between the metal insert and the surrounding portion of the bowl so that leakage occurs therebetween. In other instances, stresses are set up in that part of the bowl surrounding the insert due to the 'incompressibility of the insert during the cooling and contraction of the cast bowl. Tightening of the valve or any other added stresses which would tend even minutely to increase the insert diameter adds to the possibility of bowl failure at this point.

An object of my invention is to overcome these disadvantages of the prior art.

Another object of my invention is to provide a new and improved construction which is inexpensive, provides a perfect seal under all conditions, and does not create any high stresses in that portion of the bowl adjacent the valve mechanism.

Another object of my invention is to provide a novel construction utilizing an insert which is non-rigidly mounted and floats in its supporting bowl.

Other objects and advantages will become apparent as 1 end of the bowl taken on the line 2-2 of Fig. 1;

Fig. 3 is a horizontal sectional view through the lower end of the bowl taken on the line 3- -3 of Fig. 2;

1 Fig. 4 is a top plan view on an enlarged scale of the metal insert; and

. Fig.5 is a longitudinal sectional view of this insert. 1 I have. illustrated 'my invention asbeing incorporated in a filter indicated 'gen'efally by reference character "10 mounted in a pipe line 12 for conducting air or other fluid. The filter ltl has a plastic bowl 14 in which may be located any suitable filtering means not shown. As best shown in Fig. 2, the lower end of the bowl 14 has a twodiameter opening in which a metal sleeve or insert 16 is non-rigidly mounted. This insert has a cylindrical portion 18 located in the smaller diameter 20 which is preferably drilled of appropriate size to receive the cylindrical portionl of the insert in a free fit. The insert 16 is provided with an annular groove 22 in which is located an ring 24 of any suitable material. The O ring engages the larger diameter 26 and the opposing wall of the groove 22 to efieet an airand liquid-tight seal between the bowl Fig. 2 is an enlarged vertical sectional view of the lower 50 I 2,786,643 Patented Mar. 26, 1957 14 and insert 16, the spacing of these walls being such as to deform the 0 ring from its normal circular cross iection to an elliptical cross-section, as clearly indicated in The upper end of the insert 16 has a flange or head 28 which overlaps the inner surface of the bowl 14 and prevents the insert from being forced out of the bowl by the fluid pressure therein. The insert 16 is locked in place in the bowl by a snap ring 30 which engages an annular groove 32 formed in the lower end of the insert. As clearly shown in Fig. 2, the position of this snap ring 30 is such as to permit limited longitudinal movement of the insert in the lower end of the bowl and the O ring 24 serves to maintain an effective seal between the insert and bowl for all longitudinal positions of the insert. The bowl is provided with integral lugs 34 which engage flats 36 located on opposite sides of the head of the insert and thereby prevent rotation of this insert relative to the bowl. The insert is internally threaded as indicated at 38 and is also provided with slots 40.

The valve or cock may be of conventional construction and includes a tubular member 42 whose lower end is in the form of a nut and Whose upper end is provided with a tapered thread adapted to cooperate with the pipe thread 38 of the insert 16. A valve stem 44 is threaded into the tubular member 42 and has a handle 46 attached to its lower end. The upper end of the valve stem is enlarged as indicated at 48 and seats upon the upper end of the tubular member 42 to elfect a closure. When the valve stem 44 is rotated counterclockwise, the enlarged upper end 43 is moved upwardly and inwardly of the bowl to permit escape of fluid through a passage in valve stem 44.

The particular bowl shown in the drawing is used both for lubricators and air filters, and when used on lubricators usually does not have an insert and drain valve although sometimes so provided for lubricator use. When used without the drain valve the larger diameter forms part of a sediment trap and the end of the bowl is closed instead of being drilled out to provide the lower diameter indicated at 20 in the drawing. Where a bowl is designed solely for use with my insert and drain valve, a single diameter opening may be provided in the bottom instead of the two-diameter opening shown in the drawing. Either the single diameter or the two-diameter opening may be formed by drilling, molding, or in any other suitable manner, and the two-diameter opening need not be formed by a combination of molding and drilling as utilized in the bowl shown in the drawing. 7

The free fit between the smaller diameter 20 and the cylindrical portion 18 of the insert affords full support for the O ring 24 and prevents the fluid pressure in the bowl from forcing this 0 ring into the slight clearance between the insert and bowl. This clearance is sufficient to compensate for any small increase in diameter of the insert 16 occasioned byscrewing the valve member 42 thereinto .and thus preventstransfer of any stresses to the bowl. 14 as a resultof mounting the drain valve or cook in the .in-

sert 16 During assembly and disassembly arms valve member 42 with the insert 16, this insert is held against turning by inserting a tool in the slots 40 so that no torsional stresses are imposed upon the lugs 34. These lugs 34 seive to prevent rotation of insert 16 when the drain valve is opened and closed by turning the handle 46.

A feature of my invention resides in the non-rigid or floating mounting of the insert in the bowl which may be of plastic, glass, or other suitable material, and which may be used as part of a filter, lubricator, or other similar devices. Attention is also directed to the fact that the O ring seal is mounted in an annular chamber which is of substantially larger cross-section than the O ring, whereby any expansion of this ring due to swelling of the niater'ial thereof will not interfere with its sealing inaction or interfere with the nonri id or floating ing of the insert in the bowl,

While I have illustrated and described only a single emb dime t o my in en on, i is o e nderstood h my invention is no l mi ed to the pr cise details shown and de c ib bu may a um o h r forms, an inclu all modifications, variations, and equivalents coming within the scope of the appended claims.

I claim:

1. Means for mounting an externally threaded drain valve on a device of the class described, comprising the combination of a high strength plastic bowl having a lower part provided with a two-diameter opening, a tubular metal insert slidably mounted in said opening, said insert having an external annular groove, an O ring located insaid groove and engaging the larger diameter wall of said opening to effect a seal between said insert and .bowl, said insert having a cylindrical portion below said groove and forming a free fit with the smaller diameter 4 portion of said opening, said insert having a tapered internal thread adapted to receive the drain valve, said free fit compensating for any expansion of said insert produced by screwing the drain valve therein, a head on one end of said insert to prevent fluid pressure in said bowl from ejecting the insert therefrom, said head having opposing flats, integral lugs provided by said bowl for engaging said flats to prevent rotation of said insert relative to said bowl, a second groove provided by said insert, a snap ring located in said second groove and limiting inward movement of said insert relative to said bowl, and a slot in the head of said insert adapted to be engaged by a tool to hold said insert against rotation while the valve is screwed thereinto.

2. Means for mounting an externally threaded drain valve on a device of the class described, comprising the combination of a molded bowl having a lower part provided with a two-diameter opening, a tubular insert nonrigidly mounted in said opening, said insert having an external annular groove, sealing means located in said groove and engaging the larger diameter wall of said opening to effect a seal between said insert and bowl,

said insert having a cylindrical portion below said groove and forming a free fit with the smaller diameter portion of said opening, said insert having a tapered internal thread adapted to receive the drain valve, said free fit compensating for any expansion of said insert produced by screwing the drain valve therein, a head'on one end of said insert to prevent fluid pressure in said bowl from ejecting the insert therefrom, said head having opposing flats, integral lugs provided by said bowl for engaging said flats to prevent rotation of said insert relative to said bowl, a second groove provided by said insert, and swap ring located in said second groove and limiting inward movement of said insert relative to said bowl.

3. Means for mounting an externally threaded drain element on a device of the class described, comprising the combination of a molded bowl having an upper part adapted to be connected to a fluid conduit and a lower :part provided with an opening, a tubular insert slidably mounted in said opening, said insert and bowl providing an annular chamber therebetween, a sealing ring located in said chamber and engaging opposing walls of said insert therefrom, means for limiting inward movement of.

said insert, and means for holding said insert against roration.

4. Means for mounting an externally threaded drain element on a device of the class described, comprising the combination of a high strength bowl having a lower part provided with an opening, a tubular insert floatingly mounted in said opening, said insert having an external annular groove, an O ring located in said groove and engaging the wall of said opening to effect a seal between said insert and bowl, said insert having a cylindrical portion below said groove and forming a free fit with the wall of said opening, said insert having an internal thread adapted to receive the drain element, said free fit compensating for any expansion of said insert, means at one nd of said insert to prevent fluid pressure in said howl fIOm ejecting the insert therefrom, and other means for limiting inward movement of said insert relative to said bowl.

5. Drainable bowl means for a device of the class described, comprising a high strength bowl made of fragile material and having a lowermost part formed with a generally circular opening therein, a tubular bushing received in said opening with a free fit, said bushing having an internally threaded aperture therein, means retaining Said'bushing iii-said opening in said bowl against substan tial endwise movement and rotation, said bowl and said bushing defining an annular chamber therebetween along said opening, and a sealing ring disposed in said chamber to prevent leakage between said bowl and said bushing.

6. Drainable bowl means for a device of the class described, comprising a high strength bowl made of fragile material and having a lowermost part formed with a generally circular opening therein, a hollow drain fitting of generally circular cross section and received in said opening with a free fit, said bowl and said fitting defining anannular chamber therebetween, a sealing ring disposed in said chamber to prevent leakage between said bowl and said fitting, means retaining said fitting in said opening against substantial endwise movement, and means retaining said fitting in said opening against rotation.

- Beferenees'Cited in the file of this patent UNITED STATES PATENTS 

